Falstaff wrote:
Hello all,
Been into vintage audio for a long time ,from records to reel to reel, but have never really attempted a diy build. Also have been fascinated by tubes for awhile and have finally decided to take the plunge into both worlds. Doing lots of reading and learning so much. Hope to be able to do my first tube build probably starting with a flea watt amp. Looking forward to getting started. See you on the forums.
A few things about tubes, and then about Flea-Power, and then about DIY.
Tubes:
Are not transistors. And do not behave as transistors do. In general, watts-per-pound are many fewer. Clipping is softer, voltages are significantly (and potentially fatally) much higher, and cost-per-watt is also typically much higher, all other things being equal. With this in mind, you will need to adjust your expectations when dealing with tubes. If you have speakers that require significant power, you will need either to change them, or reduce your listening volume. Many here, including me, operate more than one system to manage those expectations. This allows one to "build" a tube based system from scratch.
Flea Power:
Bad idea if the initial foray into tubes. VDF (very dam**ed few) speakers perform well on flea power, or those that do have such a restricted dynamic range as to be very nearly useless for serious listening - unless, of course, one is listening to Gregorian Chant, solo voice, solo... well, you get the picture. And those speakers (and there are definitely some) that do perform well tend to be a mite pricey. I suggest you look into an amplifier that has at least +/-40 wpc/rms or better to start. Such an amp will give you a good introduction, and be able to drive a significant subset of good speakers available at a reasonable cost - and possibly speakers you already have.
DIY:
For your first foray, I suggest you look for an established kit, not a circuit that you are going to build yourself from a schematic. There are a lot of peripheral skills required for this (which, of course, you may already have) including manipulating sheet metal or punching an already made chassis, picking out the various transformers and more, then assembling the circuit, then testing and more. Or, consider purchasing a basic, well-supported amplifier already made (the Dynaco ST70 leaps to mind), and go through the many dozens of after-market modifications as may be made to it - and learn from an established design.
In any case, there is much to learn about this ancient technology. And best of luck with it. Enjoy!